This invention pertains to a devices for maintaining and controlling the water level in a basin, and in particular to a device for automatically controlling the flow of water into the basin dependent upon the water level in the basin.
When a basin, such as a bathtub, is being filled, ordinarily it is necessary for the bathtub to be attended during the filling procedure so that a desired water level is attained and there is no overflow. Should the person monitoring the filling of the bathtub be called away for any reason while water is running, the risk of overflow or over filling remains, wasting water and potentially causing water damage if an overflow occurs.
Water level control systems have been developed to automatically control the water level in a bathtub. For example, U.S. Pat. No. 4,042,984 discloses a complex electronic system for doing so. While the water level is monitored, the complexity of the control makes it prohibitively expensive. In addition, use of electricity near the bathtub creates a potential shock hazzard.
U.S. Pat. No. 1,744,073 discloses a device for automatically controlling the flow from a faucet which uses a float disposed in a separate housing attached to the bathtub. Because of the use of a float and the nature of the apparatus, it is difficult to vary the water level to any substantial degree. Also, over time, the float could lose it buoyancy, and because it is hidden behind the bathtub, a costly reconstruction effort might be necessary.
U.S. Pat. Nos. 2,687,740; 3,344,804 and 3,545,481 disclosed devices for controlling liquid level using air pressure. However, in each of the devices, air pressure is used to actuate a microswitch and other electronics are used to control the water flow. Such devices are quite costly to construct, and in the environment of a bathtub, having electronics near the tub creates the potential of dangerous shock.
A purely mechanical device for controlling the water level is disclosed in U.S. Pat. No. 3,805,822. However, the device is quite complex, using many parts, and is therefore commensurately expensive to construct. The many moving parts invite premature failure and costly repair.
U.S. Pat. No. 1,537,915 discloses a simple mechanical device for terminating the unattended water flow into a bathtub. However, the only time that the device is actuated is when water enters the bathtub overflow. There is no means of varying the ultimate water level if the device is used.